//package com.hzz.hzzcloud.util.snowflake算法;
//
///**
// * @author ：hzz
// * @description：TODO
// * @date ：2020/8/25 16:10
// */
//public class IdWorker {
//    private long workerId;
//    private long datacenterId;
//    private long sequence;
//    public IdWorker(long workerId, long datacenterId, long sequence) {
//        // sanity check for workerId
//        // 这儿不就检查了一下，要求就是你传递进来的机房id和机器id不能超过32，不能小于0
//        if (workerId > maxWorkerId || workerId < 0) {
//            throw new IllegalArgumentException(
//                    String.format("worker Id can't be greater than %d or less than 0", maxWorkerId));
//        }
//        if (datacenterId > maxDatacenterId || datacenterId < 0) {
//            throw new IllegalArgumentException(
//                    String.format("datacenter Id can't be greater than %d or less than 0", maxDatacenterId));
//        }
//        System.out.printf(
//                "worker starting. timestamp left shift %d, datacenter id bits %d, worker id bits %d, equence bits %d, workerid %d",
//                timestampLeftShift, datacenterIdBits, workerIdBits, sequenceBits, workerId);
//        this.workerId = workerId;
//        this.datacenterId = datacenterId;
//        this.sequence = sequence;
//    }
//    private long twepoch = 1288834974657L;
//    private long workerIdBits = 5L;
//    private long datacenterIdBits = 5L;
//    // 这个是二进制运算，就是 5 bit最多只能有31个数字，也就是说机器id最多只能是32以内
//    private long maxWorkerId = -1L ^ (-1L << workerIdBits);
//    // 这个是一个意思，就是 5 bit最多只能有31个数字，机房id最多只能是32以内
//    private long maxDatacenterId = -1L ^ (-1L << datacenterIdBits);
//    private long sequenceBits = 12L;
//    private long workerIdShift = sequenceBits;
//    private long datacenterIdShift = sequenceBits + workerIdBits
//    private long timestampLeftShift = sequenceBits + workerIdBits + datacenterIdBits;
//    private long sequenceMask = -1L ^ (-1L << sequenceBits);
//    private long lastTimestamp = -1L;
//    public long getWorkerId() {
//        return workerId;
//    }
//    public long getDatacenterId() {
//        return datacenterId;
//    }
//    public long getTimestamp() {
//        return System.currentTimeMillis();
//    }
//    public synchronized long nextId() {
//        // 这儿就是获取当前时间戳，单位是毫秒
//        long timestamp = timeGen();
//        if (timestamp < lastTimestamp) {
//            System.err.printf("clock is moving backwards.  Rejecting requests until %d.", lastTimestamp);
//            throw new RuntimeException(String.format(
//                    "Clock moved backwards.  Refusing to generate id for %d milliseconds", lastTimestamp - timestamp));
//        }
//        if (lastTimestamp == timestamp) {
//            // 这个意思是说一个毫秒内最多只能有4096个数字
//            // 无论你传递多少进来，这个位运算保证始终就是在4096这个范围内，避免你自己传递个sequence超过了4096这个范围
//            sequence = (sequence + 1) & sequenceMask;
//            if(sequence == 0) {
//                timestamp = tilNextMillis(lastTimestamp);
//            }
//        } else {
//            sequence = 0;
//        }
//        // 这儿记录一下最近一次生成id的时间戳，单位是毫秒
//        lastTimestamp = timestamp;
//        // 这儿就是将时间戳左移，放到 41 bit那儿；
//        // 将机房 id左移放到 5 bit那儿；
//        // 将机器id左移放到5 bit那儿；将序号放最后12 bit；
//        // 最后拼接起来成一个 64 bit的二进制数字，转换成 10 进制就是个 long 型
//        return ((timestamp - twepoch) << timestampLeftShift) | (datacenterId << atacenterIdShift)
//                | (workerId << workerIdShift) | sequence;
//    }
//    private long tilNextMillis(long lastTimestamp) {
//        long timestamp = timeGen();
//        while (timestamp <= lastTimestamp) {
//            timestamp = timeGen();
//        }
//        return timestamp;
//    }
//    private long timeGen() {
//        return System.currentTimeMillis();
//    }
//    // ---------------测试---------------
//    public static void main(String[] args) {
//        IdWorker worker = new IdWorker(1, 1, 1);
//        for (int i = 0; i < 30; i++) {
//            System.out.println(worker.nextId());
//        }
//    }
//}